IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change

Emission trends (global and regional)

Direct GHG emissions from industry are currently about 7.2 GtCO2-eq. As the mitigation options discussed in this chapter include measures aimed at reducing the industrial use of electricity, emissions including those from electricity use are important for comparison. Total industrial sector GHG emissions were about 12 GtCO2-eq in 2004, about 25% of the global total. CO2 emissions (including electricity use) from the industrial sector grew from 6.0 GtCO2 in 1971 to 9.9 GtCO2 in 2004. In 2004, developed nations accounted for 35% of total energy-related CO2 emissions, economies in transition for 11% and developing nations for 53% (see Figure TS.18). Industry also emits CO2 from non-energy uses of fossil fuels and from non-fossil fuel sources. In 2000, these were estimated to total 1.7 GtCO2 (high agreement, much evidence) [7.1.3].

Figure TS.18

Figure TS.18: Industrial sector energy-related CO2 emissions (GtCO2; including electricity use), 1971–2030. [Table 7.1, 7.2].

Note: Dark red – historic emissions; light red – projections according to SRES B2 scenario. Data extracted from Price et al. (2006).

EECCA = Countries of Eastern Europe, the Caucasus and Central Asia.

Industrial processes also emit other GHGs, including HFC-23 from the manufacture of HCFC-22; PFCs from aluminium smelting and semiconductor processing; SF6 from use in flat panel screens (liquid crystal display) and semi-conductors, magnesium die casting, electrical equipment, aluminium melting, and others, and CH4 and N2O from chemical industry sources and food-industry waste streams. Total emission from these sources was about 0.4 GtCO2-eq in 2000 (medium agreement, medium evidence) [7.1.3].

The projections for industrial CO2 emissions for 2030 under the SRES-B22 scenarios are around 14 GtCO2 (including electricity use) (see Figure TS.18). The highest average growth rates in industrial-sector CO2 emissions are projected for developing countries. Growth in the regions of Central and Eastern Europe, the Caucasus and Central Asia, and Developing Asia is projected to slow in both scenarios for 2000–2030. CO2 emissions are expected to decline in the Pacific OECD, North America and Western Europe regions for B2 after 2010. For non-CO2 GHG emissions from the industrial sector, emissions by 2030 are projected to increase globally by a factor of 1.4, from 470 MtCO2-eq. (130 MtC-eq) in 1990 to 670 MtCO2-eq (180 MtC-eq.) in 2030 assuming no further action is taken to control these emissions. Mitigation efforts led to a decrease in non-CO2 GHG emissions between 1990 and 2000, and many programmes for additional control are underway (see Table TS.9) (high agreement, medium evidence) [7.1.3].

Table TS.9: Projected industrial sector emissions of non-CO2 GHGs, MtCO2-eq/yr [Table 7.3].

Region 1990 2000 2010 2030 
Pacific OECD  38 53 47 49 
North America 147 117 96 147 
Western Europe 159 96 92 109 
Central and Eastern Europe 31 21 22 27 
EECCA 37 20 21 26 
Developing Asia 34 91 118 230 
Latin America 17 18 21 38 
Sub Saharan Africa 10 11 21 
Middle East and North Africa 10 20 
World 470 428 438 668 


Emissions from refrigeration equipment used in industrial processes included; emissions from all other refrigeration and air-conditioning applications excluded.

Description and assessment of mitigation technologies and practices, options and potentials, costs and sustainability

Historically, the industrial sector has achieved reductions in energy intensity and emission intensity through adoption of energy efficiency and specific mitigation technologies, particularly in energy-intensive industries. The aluminium industry reported >70% reduction in PFC-emission intensity over the period 1990–2004 and the ammonia industry reported that plants designed in 2004 have a 50% reduction in energy intensity compared with those designed in 1960. Continuing to modernize ammonia-production facilities around the world will result in further energy-efficiency improvements. Reductions in refining energy intensity have also been reported [7.4.2, 7.4.3, 7.4.4].

The low technical and economic capacity of SMEs pose challenges for the diffusion of sound environmental technology, though some innovative R&D is taking place in SMEs.

A wide range of measures and technologies have the potential to reduce industrial GHG emissions. These technologies can be grouped into the categories of energy efficiency, fuel switching, power recovery, renewables, feedstock change, product change and material efficiency (Table TS.10). Within each category, some technologies, such as the use of more efficient electric motors, are broadly applicable across all industries, while others, such as top-gas pressure recovery in blast furnaces, are process-specific.

Table TS.10: Examples of industrial technology for reducing GHG emissions (not comprehensive). Technologies in italics are under demonstration or development [Table 7.5].

Sector Energy efficiency Fuel switching Power recovery Renewables Feedstock change Product change Material efficiency Non-CO2 GHG CO2 capture and storage 

Sector wide


Benchmarking; Energy management systems; Efficient motor systems, boilers, furnaces, lighting and heating/ventilation/air conditioning;

Process integration


Coal to natural gas and oil




Biomass, Biogas, PV, Wind turbines, Hydropower


Recycled inputs





Oxy-fuel combustion, CO2 separation from flue gas


Iron & steel


Smelt reduction, Near net shape casting, Scrap preheating, Dry coke quenching


Natural gas, oil or plastic injection into the BF


Top-gas pressure recovery, By-product gas combined cycle






High strength steel


Recycling, High strength steel, Reduction process losses




Hydrogen reduction,

oxygen use in blast furnaces


Non-ferrous metals


Inert anodes,

Efficient cell designs








Recycling, thinner film and coating


PFC/SF6 controls





Membrane separations, Reactive distillation


Natural gas


Pre-coupled gas turbine, Pressure recovery turbine, H2 recovery



Recycled plastics, bio-feedstock


Linear low density polyethylene, high-perf. plastics


Recycling, Thinner film and coating, Reduced process losses


N2O, PFCs, CFCs and HFCs control


CO2 storage from ammonia, ethylene oxide processes


Petroleum refining


Membrane separation

Refinery gas


Natural gas


Pressure recovery turbine, hydrogen recovery







(reduction in transport not included here)


Control technology for N2O/CH4


From hydrogen production




Precalciner kiln, Roller mill, fluidized bed kiln


Waste fuels, Biogas, Biomass


Drying with gas turbine, power recovery


Biomass fuels, Biogas


Slags, pozzolanes


Blended cement






Oxyfuel combustion in kiln




Cullet preheating

Oxyfuel furnace


Natural gas


Air bottoming cycle




Increased cullet use


High-strength thin containers






OxyfuelL combustion


Pulp and paper


Efficient pulping, Efficient drying, Shoe press, Condebelt drying


Biomass, Landfill gas


Black liquor gasification combined cycle


Biomass fuels (bark, black liquor)


Recycling, Non-wood fibres


Fibre orientation, Thinner paper


Reduction cutting and process losses




Oxyfuel combustion in lime kiln




Efficient drying, Membranes


Biogas, Natural gas


Anaerobic digestion, Gasification


Biomass, By-products, Solar drying




Reduction process losses, Closed water use




Later in the period to 2030, there will be a substantial additional potential from further energy- efficiency improvements and application of Carbon Capture and Storage (CCS)[17] and non-GHG process technologies. Examples of such new technologies that are currently in the R&D phase include inert electrodes for aluminium manufacture and hydrogen for metal production (high agreement, much evidence) [7.2, 7.3, 7.4].

Mitigation potentials and costs in 2030 have been estimated in an industry-by-industry assessment of energy-intensive industries and an overall assessment of other industries. The approach yielded mitigation potentials of about 1.1 GtCO2-eq at a cost of <20 US$/tCO2 (74 US$/tC-eq); about 3.5 GtCO2-eq at costs below <50 US$/tCO2 (180 US$/tC-eq); and about 4 GtCO2-eq/yr (0.60–1.4 GtC-eq/yr) at costs <US$100/tCO2-eq (<US$370/tC-eq) under the B2 scenario. The largest mitigation potentials are in the steel, cement and pulp and paper industries, and in the control of non-CO2 gases, and much of the potential is available at <50 US$/tCO2-eq (<US$ 180/tC-eq). Application of CCS technology offers a large additional potential, albeit at higher cost.

A recently completed global study for nine groups of technologies indicates a mitigation potential for the industrial sector of 2.5-3.0 GtCO2-eq/yr (0.68-0.82 GtC-eq/yr) in 2030 at costs of <25 US$/tCO2 (< 92US$/tC) (2004$). While the estimate of mitigation potential is in the range found in this assessment, the estimate of mitigation cost is significantly lower (medium agreement, medium evidence) [7.5].

  1. ^  See IPCC Special Report on CO2 Capture and Storage